Studies on Genetic Divergence in Table Pea [Pisum sativum (L.) Spp. Hortense]

Abstract

The present investigation entitled, "Assessment of genetic diversity in garlic (Allium sativum L.), using morphological and molecular markers" involving fifteen genotypes was undertaken to examine the genetic variability, heritability, genetic advance, correlation coefficient, path coefficient analysis, genetic divergence and molecular characterization. All the fifteen Indian garlic genotypes were tested in randomized block design with 3 replications during rabi season 2013-14. The results showed high (GCV) and (PCV), for traits like (>25 %) was observed in single cloves weight (33.9, and 38. 1), bulb weight (30.9, and 31.1), leaves per plant at 30 DAP (26.2, and 29.2). High heritability values were obtained for all the characters under study. High heritability estimates coupled with high genetic advance as per cent of mean (genetic gain) was observed for high heritability (>60%) was recorded for the among all characters of viz. Bulb diameter (98%), leaf length at 90 DAP (99%), bulb weight (98.40), cloves per bulb (95.90), leaf length at 60 DAP (97%).Genetic advance (GA) at 5% selection intensity and percentage of mean for various quantitative characters is , expressed as percentage of mean was observed high (>20%) for cloves per bulb (38.24), single cloves weight (62.12), bulb weight (63.28), leaf length 30 DAP (48.17), leaf per plant at 30 DAP (48.45). Genetic divergence, method of Mahalanobis 'D2 ' statistic results indicated that ,the total of 4 genotypes fell into cluster I, 4 genotypes in cluster II, 7 genotypes fell in to cluster Ill and the maximum inter cluster D2 value (6.294) was recorded between cluster II and I. whereas the minimum average inter cluster D2 value (3.250) was recorded between clusters -1 and I. The intra. cluster divergence were found to range between 3.250 for cluster I, 4.254 for cluster II, 5.654 for cluster III , so, these characters can be easily imp-proved by selection methods and through individual plant selection. Eight SSR primers generated 22 bands, ranged from (0.16 to 1.02 kbp size range) with an average of 2.75 bands per primer and the polymorphic Information content (PIC) varied from 0.00 to 0.84 with an average 0.47 , while resolving power (rp) was in the ranged from 1.86 to 4.53, with an average 2.63 . Marker index (MI) varied from 0.00 to 24.22 with an average 4.71. Significant genetic variation was found among all garlic cultivars with the GS value ranging from (0.36) to (1.00) with a mean of (0.68). The UPGMA based on the clustering grouped 15 garlic genotypes in to two major groups i.e. I and II groups. Groups II had maximum number of genotypes (8) fallowed by group I i.e. (7) genotypes were found respectively. This envisaged that the genotypes grouped within a particular cluster are more or less genetically similar to each other and apparent wide diversity is mainly due to the remaining genotype distributed over rest of the other cluster. Divergence morphological and molecular study suggested that the genotypes like Sukha- 44, G-50, Bhima Purpule, PG-17, PG-35, BG-108, and A-VTG-l,crosses are expected to provide for getting desired se gates from breeding point of view.